# #for 循环
# total = 0
# for i in range(1,10):
#     total = total + i
# print(total)
total = 0
count = 0
user_input=input("请输入数字：")
while user_input != "q":
    num=float(user_input)
    total = total + num
    count = count +1
    user_input = input("请输入数字：")
if count==0:
    result=0
else:
    result = total/count
print(result)